Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
  • F03C1/00—Reciprocating-piston liquid engines
  • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
  • F03C1/06—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis
  • F03C1/0678—Control
  • F03C1/0694—Control by changing the inclination of the axis of the cylinder barrel in relation to the axis of the actuated element
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
  • F03C1/00—Reciprocating-piston liquid engines
  • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
  • F03C1/06—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis
  • F03C1/0636—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
  • F03C1/0644—Component parts
  • F03C1/0668—Swash or actuated plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
  • F03C1/00—Reciprocating-piston liquid engines
  • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
  • F03C1/06—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinder axes generally coaxial with, or parallel or inclined to, main shaft axis
  • F03C1/0678—Control
  • F03C1/0686—Control by changing the inclination of the swash plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
  • F04B1/12—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis
  • F04B1/20—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block
  • F04B1/22—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block having two or more sets of cylinders or pistons
  • F04B1/24—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinder axes coaxial with, or parallel or inclined to, main shaft axis having rotary cylinder block having two or more sets of cylinders or pistons inclined to the main shaft axis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2201/00—Pump parameters
  • F04B2201/12—Parameters of driving or driven means
  • F04B2201/1204—Position of a rotating inclined plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2201/00—Pump parameters
  • F04B2201/12—Parameters of driving or driven means
  • F04B2201/1204—Position of a rotating inclined plate
  • F04B2201/12041—Angular position
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2201/00—Pump parameters
  • F04B2201/12—Parameters of driving or driven means
  • F04B2201/1205—Position of a non-rotating inclined plate
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B2201/00—Pump parameters
  • F04B2201/12—Parameters of driving or driven means
  • F04B2201/1205—Position of a non-rotating inclined plate
  • F04B2201/12051—Angular position

Definitions

• the invention relates to an axial piston machine with variable displacement.
• the invention can be used in an axial piston motor/pump with variable displacement of the type with a tilted body, for example of the type with a tilted disc or with a tilted cylinder block.
• the invention relates to a machine comprising a rotating shaft, a rotating cylinder block connected to said shaft, at least one piston slidable with reciprocal movement in said cylinder block, and a tilted body coupled with said cylinder block or with said at least one piston, wherein the displacement of said at least one piston depends on the tilt of said tilted body.
• One known system for measuring the angle of tilt of the tilted body comprises a rotating sensor positioned on the plane of the ball joints coupled with the rotating shaft.
• Another known system involves using sensors connected mechanically (typically by levers and/or transmissions) to the actuating piston that moves the tilted body.
• Another improvable aspect is to increase the operating duration of the monitoring system.
• One object of the invention is to provide a piston machine with variable displacement that is able to improve one or more of the aspects of the prior art indicated above.
• One advantage is to increase the operating duration of the displacement monitoring system, in particular owing to the fact that there are no reciprocally sliding sensor operating parts, the possibility of wear through sliding being thus avoided. Further, the operating duration can be high because there are no sensor operating parts communicating with relatively high-pressure zones of the machine .
• One advantage is to make a displacement monitoring system available that is easy to assemble.
• the system can be easy to assemble if the sensor comprises two parts that communicate with one another at a distance without reciprocal contact, in which a first part is inserted into a first seat obtained on a body with a tilt that is variable with respect to the motor shaft (in which the displacement of the machine depends on the aforesaid tilt), and a second part is inserted into a second seat obtained on a fixed body.
• One advantage is not to modify substantially the inertia of moving masses in the context of the piston machine (for example motor) , so it is possible to obtain the same machine response speed during displacement variation.
• the monitoring system does not substantially have sensor parts that connected to rotating elements of the machine.
• the monitoring system is able to monitor directly and without contact the movement and/or the position of the tilted body (in particular of the distributor operationally associated with the piston/s of the cylinder block) .
• the monitoring system does not require mechanical connection (for example transmissions or the like) to detect the (angular) position of the tilted body, thus avoiding measuring errors due, for example, to deformation of mechanical parts.
• Figure 1 is a section of a machine made according to the invention.
• Figure 2 is a prospective view of a part of the machine in figure 1, with the position sensor of the tilted body in a first operating configuration.
• Figure 3 is a top view of the aforesaid machine part in the first operating configuration.
• Figure 4 is a prospective view of the aforesaid machine part in a second operating configuration.
• Figure 5 is a top view of the aforesaid machine part in the second operating configuration.
• Figure 6 is a prospective view of the aforesaid machine part in a third operating configuration.
• Figure 7 is a top view of the aforesaid machine part in the third operating configuration.
• Figures 8 to 10 are three side views of the aforesaid machine part, respectively in the first, second and third configuration .
• the machine 1 comprises a distributor 7 having a first face coupled with the rotating cylinder block 3.
• the distributor 7 may have a tilt (with respect to the rotating shaft 2) .
• the tilt of the distributor 7 (with respect to the rotating shaft 2) will be the same as the tilt of the rotating cylinder block 3 (with respect to the rotating shaft 2) .
• the first face has a first entry port 8 (supply or aspiration) and a second outlet port 9 (discharge or delivery) for an operating fluid (liquid, for example oil) operationally associated with each slidable piston 5.
• the cylinder block 3 will rotate on the fixed distributor 7. Through the effect of the rotation of the cylinder block 3, the piston 5 (which rotates with the cylinder block 3) will be placed in communication with the first port 8 and with the second port 9 alternately.
• the cylinder block 3 and the distributor 7 are coupled together in such a manner as to enable the cylinder block 3 to rotate with respect to the distributor 7. Further, the cylinder block 3 and the distributor 7 are coupled together in such a manner that each tilt variation of the distributor 7 (with respect to the rotating shaft 2) is matched by the same tilt variation of the cylinder block 3 (with respect to the rotating shaft 2) .
• the displacement of the slidable piston 5, and thus of the machine will depend on the tilt of the cylinder block 3 and of the distributor 7 (with respect to the rotating shaft 2) .
• the distributor 7 is slidably coupled on a sliding guide 10 that guides the distributor 7 along a circular arch path.
• the guide 10 is arranged on a fixed machine part.
• the distributor 7 thus gives rise to a tilted body coupled with a fixed machine part such a manner as to vary the tilt and thus the displacement of the slidable piston 5.
• the actuator 11 may comprise, as in the specific case, a linear actuator mechanically coupled with a second face of the distributor 7 opposite the first face.
• a (linear) movement of the movable element (piston) of the actuator 11 causes a variation in the tilt of the distributor 7 and thus of the cylinder block 3.
• the machine is provided with a position sensor configured for detecting the position, and thus the tilt with respect to the axis of the rotating shaft 2, of the tilted body (distributor 7 and/or cylinder block 3 that have the same tilt) .
• the sensor may comprise, as in the specific case, a first part 14 and a second part 15, wherein the first part 14 may be mounted on the distributor 7 and the second part 15 may be mounted on the fixed machine part, i.e. on a machine part the position of which (in particular the tilt or the orientation) is not modified with respect to the axis of the motor shaft 2.
• the second part 15 of the sensor may be mounted, in particular, on the cover 13.
• the second part 15 of the sensor may be, as in the specific case, connected to the first part 14 in a contactless mode, with the possibility of detecting the position of the first part 14.
• the contactless mode may be achieved, for example, with inductive, capacitive, magnetic, ultrasound, optic, etc. position sensors.
• the position sensor may comprise, as in the specific case, a magnetorestrictive sensor, for example a linear sensor.
• the first part 14 of sensor may also comprise a magnet and the second part 15 may comprise a sensor rod that is sensitive to the position of the magnet.
• the distributor 7 has at least one side that extends from a side edge of the first face and/or of the second face.
• this side of the distributor 7 may be a side of the distributor that joins the first face to the second face.
• the side of the distributor 7 may be, as in the specific case, substantially parallel to the axis of the linear actuator 11.
• the aforesaid side will, in particular, be the side of the distributor 7 nearest of the linear actuator 11.
• This side has a recess in which the magnet of the magnetorestrictive sensor is housed.
• the first part 14 of sensor may be connected integrally with the distributor 7, for example by means of coupling with interference by means of forcing of the magnet inside the recess .
• the linear actuator 11 may be, as in the specific case, parallel to the sensor rod (second part 15 of sensor) .
• the sensor rod may be, as in the specific case, parallel to the side of the distributor 7 that bears the magnet.
• the cover 13 may have a hole in which the second part 15 of sensor (sensor rod) is housed.
• the first part 14 and the second part 15 of sensor face one another and are spaced apart by a separating gap filled with a fluid (for example a liquid, like oil) .
• the gap may be, as in the specific case, at a relatively low pressure, in particular with respect to the operating pressures of the piston 5 and of the actuator 11.
• the gap may be insulated such as to be fluid- tight with respect to zones communicating with the operating fluid of the piston 5.
• the gap may be insulated such as to be fluid-tight with respect to high- pressure zones of the operating fluid of the actuator 11.
• the two parts, 14 and 15, of sensor may be arranged, for example, at a mutual distance comprised between 1 and 20 mm, for example at about 8 mm.
• the second part 15 of sensor will be sensitive to the position of the first part 14 of sensor along the entire stroke of the distributor 7 (the ends of the stroke of the distributor 7 correspond to the second and third configuration of the attached figures) .
• the sensor rod may emit a signal indicating the distance of the magnet from the base of the sensor rod.
• the control unit will be programmed in such a manner as to determine the tilt of the distributor 7 as a function of the position signal of the first part 14 of sensor (magnet) . On the basis of this tilt, the control unit can thus determine, in real time, the actual displacement of the piston 5 and of the machine.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Reciprocating Pumps (AREA)
• Details Of Reciprocating Pumps (AREA)
• Actuator (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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ID=43533440

Family Applications (1)

Country Status (4)

Cited By (5)

Citations (9)

Family Cites Families (1)

• 2010
  • 2010-07-26 IT ITMO2010A000215A patent/IT1401174B1/it active
• 2011
  • 2011-07-21 CN CN201180036426.7A patent/CN103026055B/zh active Active
  • 2011-07-21 WO PCT/IB2011/053249 patent/WO2012014128A1/en active Application Filing
  • 2011-07-21 EP EP11746648.2A patent/EP2598749B1/en active Active

Patent Citations (9)

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